HOUSTON - NASA will preview an upcoming spacewalk from the International Space Station and provide an update on other station activities at 1 p.m. CDT on July 18. NASA Television will provide live coverage of the briefing and the July 23 spacewalk. During the briefing from Johnson Space Center, media may ask questions from other NASA sites. Reporters should call their local NASA center to confirm its participation in the event.

The participants are:

- Bob Dempsey, Expedition 15 lead flight director

- Daryl Schuck, Expedition 15 lead spacewalk officer

On July 23, Expedition 15 Flight Engineer Clay Anderson and Commander Fyodor Yurchikhin will don U.S. spacesuits and float out of the complex's Quest airlock at approximately 5:30 a.m. CDT. NASA TV coverage will begin at 5 a.m. The objectives of the 6.5-hour spacewalk are to replace a failed power controller on the station's truss, jettison a refrigerator-sized ammonia reservoir tank and clean seals on a docking port on the Unity module.

Other upcoming station activities include the Aug. 2 launch of a new Russian Progress cargo ship from the Baikonur Cosmodrome in Kazakhstan. Carrying 2.5 tons of food, fuel, spare parts and other supplies, the ISS Progress 26 will dock to the station on Aug. 5. Among the supplies are new Russian computers and computer components. NASA TV will broadcast the Progress' arrival beginning at 1 p.m. CDT. Docking is scheduled at 1:37 p.m.

For NASA TV downlink, schedule and streaming video information, visit:

http://www.nasa.gov/ntv